A/C Running Temps? (1 Viewer)

[lcolon]

I searched but...

Per the saga on my other thread, I have done the top end, manifold, and gone through the whole cooling system on my cruiser. I finally have it running 190o ish under normal driving conditions without the A/C on. I took the rig over memorial day for a real shakedown run from Nor Cal to Joshua Tree, some wheeling, and back. Crossing the Mohave desert yesterday at 65-70mph with the A/C blasting on High my temps climbed to 212o and held steady. When exiting the freeway seemed to get hotter and the stock gauge was still in the white but almost to overheating (spiked up close to 220o but not quite there).

When the A/C is off, max is around 200o (climbing up 58 over the pass in Tehachapi).

The temps in the Mohave desert were around 90-95oF. I am continuing to be paranoid about cooling on the cruiser so I would appreciate any baselines that people have regarding hot outside temps with A/C.

Today I did replace the "champion" radiator cap on the aluminum radiator with a seiki unit. There are no coolant leaks that I can detect. I do have some kind of exhaust leak that I need to track down (sucks as I just did the manifold gaskets). It may be the j-pipe gasket but more investigation is required. No difference in running temps (heat wave in the bay area)

Do temps of 212o with 90-95o outside seem correct or are there more issues I need to chase down?

 

[pithicus]

My fj73 3f auto struggles at 90-100 degrees f. I have to turn off the a/c occasionally on the hwy @ 100kmph, especially over 100 f. 70 mph would probably overheat the system i'm sure. It has never boiled yet, but gets close to the red mark on the temp gauge. Don't know what the temp actually gets too with just the gauge. Around town is usually ok.
My cooling system is in ok condition. It used to cope better, so might just need a good flush.

 

[vipergrhd]

Did you check if your fan clutch is engaging? I would install a real temp. gauge i won't trust the factory gauge.

 

[pithicus]

Did you check if your fan clutch is engaging?

It works good. Really roars. The temps drops really fast when I turn the a/c off. Puts quite a strain on the old truck.

 

[joebattle1]

I am literally fighting the same demons.

 

[BlackCat]

My 60 will see 215-220 with the A/C on idling in traffic in 110F+ temps in Phoenix.
In 95-100+ temps, the gauge will go over half way, but my infra red temp gauge says the truck is generally in the 200F range.
Unknown age of fan clutch in my truck (possibly original) and unknown brand/age of thermostat. I do have an aluminum Mishimoto radiator.

 

[lcolon]

Thank you all for your replies. It looks like I am in the "zone". 215-220 seems very hot for the 2F but I guess that is what it is. I would normally turn off the A/C if I hit those temps.

 

[SteveH]

I'm about to install a 180 degree t-stat in my FJ62, vs. the factory 190 degree t-stat. I have an old one from an FJ40 and it would be interesting to see if that makes any difference on the gauge.

 

[lcolon]

I have been running a 180o thermostat since I first got the truck. I also finally installed a mechanical gauge in-line with the upper radiator hose. That allows the stock gauge to remain where it is while measuring the actual temps of the coolant. It has provided quite a bit of insight and now I don't have to go crazy with my IR gun trying to figure out temps under the hood.

 

[2mbb]

I'm not sure that 220F is overheating. At least the cap should hold back the pressure. I think the radiator cap is 13psi which should hold for temperatures up to 245-250F... for water. I think antifreeze should have a higher boiling point.

 

[pithicus]

A new radiator would probably fix my issues.
Also the hotter t-stat seems to be better . Really appreciated in winter, and actually seems to perform better in really hot weather.

 

[vipergrhd]

Just wondering what was your temp reading at the hose? is it close to the original gauge?

I have been running a 180o thermostat since I first got the truck. I also finally installed a mechanical gauge in-line with the upper radiator hose. That allows the stock gauge to remain where it is while measuring the actual temps of the coolant. It has provided quite a bit of insight and now I don't have to go crazy with my IR gun trying to figure out temps under the hood.

 

[lcolon]

Just wondering what was your temp reading at the hose? is it close to the original gauge?

It actually is. I ran the mechanical gauge in the standard head location where the OEM sender is for a while. The problem with that location is that given the number of pipe fittings required to get the long mechanical sender to work, it can gather air bubbles. By using the upper radiator hose, I can use both the stock gauge and the mechanical at the same time. The mechanical will not read anything until the thermostat opens, but it is accurate after that.

I used this fitting to hook it up:
Steiger Performance Inline Radiator Hose Temperature Sensor Adapter for 1.5 inch (38mm) hose, 3/8 NPT

 

[toy_tek]

62/3fe here. Logged in to mud today regarding temps, glad to see this. I have new brass rad, new wp, new tstat (180 iirc), flushed system, all new hoses, new fj80 Aisan fan clutch. Have had some stock gauge spikes so recently installed an auto meter elec gauge w sender in the top hose. I confirmed the gauge reads pretty accurate (to IR gun at tstat housing). Up until this week I was seeing 180-190 around town and hwy w ac. This week (100+ Outside) I’m seeing 210-225 on hwy w AC on. I can hear the fan cycle on at about 210-215. My only concern is that this truck is unloaded and basically stock, and I haven’t even tried driving the hill on 17 north yet.

 

[lcolon]

I actually drove out to Valley Hybrids today to check out different bumpers on cruisers as I am looking to get a swing-out bumper and long range tank. As I was talking to Georg, he basically told me that the 88oc (190oF) is the thermostat to use in the FJ60. I have the complete kit at home to put a pusher fan on the front of the condenser. Based on my conversation with Georg, I am going to change out my 180oF thermostat for the factory one. He told me it will actually run better hot as the greater restriction at higher temps allows the coolant to sit longer in the radiator and cool down. The 180o free flows earlier which lessens the cooling action. Some additional searches here on mud seem to confirm similar. Going to do that first and if I still have a problem look at doing the pusher. It helps that I have one sitting in the garage.

I was seeing with the 180o 210-214 on the highway in 95+o weather in the desert. Will see if this change improves anything. I can say that I am tired of cracking open my cooling system, losing a bunch of coolant, burping, and the whole nine yards. I have 10 gallons of coolant waiting to go to recycling already. I am hesitant to use any stuff that touches greasy parts on its way down to a bucket.

 

[pithicus]

the greater restriction at higher temps allows the coolant to sit longer in the radiator and cool down.

That's a good description, and it was exactly what happened in my t-stat testing.
The hotter t-stat is definitely the best option.